CN112808308A

CN112808308A - Preparation method and application of visible light response organic-inorganic hybrid membrane

Info

Publication number: CN112808308A
Application number: CN202011552800.6A
Authority: CN
Inventors: 王晓虹; 杨慧芝; 左宇璐; 王思甜; 候坤; 蹇建; 周虎
Original assignee: Hunan University of Science and Technology
Current assignee: Hunan University of Science and Technology
Priority date: 2020-12-24
Filing date: 2020-12-24
Publication date: 2021-05-18
Anticipated expiration: 2040-12-24
Also published as: CN112808308B

Abstract

The invention relates to the technical field of organic-inorganic hybrid materials, and particularly discloses a preparation method and application of a visible light response organic-inorganic hybrid membrane, wherein the method comprises the following steps: the preparation method comprises the steps of contacting and mixing a silver nitrate solution and polyurethane to dissolve, then contacting the mixed solution with sepiolite and cerium oxide in sequence to obtain a coating solution, distributing the coating solution on a substrate, carrying out contact reaction on the substrate coated with the coating solution and a YX solution to obtain a hybrid membrane deposited with in-situ generated AgX nano particles, drying the hybrid membrane and illuminating under an ultraviolet lamp to obtain the visible-light-responsive organic-inorganic hybrid membrane. The organic-inorganic hybrid membrane prepared by the invention has excellent visible light response photocatalysis performance, can be used as an efficient antibacterial material, has better antibacterial capability, is simple in preparation method, and is stable in structure and easy to recover.

Description

Preparation method and application of visible light response organic-inorganic hybrid membrane

Technical Field

The invention belongs to the technical field of organic-inorganic hybrid materials, and particularly relates to a preparation method and application of a visible light response organic-inorganic hybrid membrane.

Background

The photocatalysis is that under the condition of certain wavelength illumination, the semiconductor material generates the separation of photon-generated carriers, then photon-generated electrons and holes are combined with ions or molecules to generate active free radicals with oxidability or reducibility, the active free radicals can degrade organic macromolecules into carbon dioxide or other micromolecular organic matters and water, and the semiconductor material, namely the photocatalyst, does not change in the reaction process.

The photocatalysis technology is a novel high-efficiency clean water treatment technology, can treat various refractory organic pollutants, has good sterilization and bacteriostatic activity, has few byproducts, is nontoxic and harmless, and has the remarkable advantages of low energy consumption, environmental friendliness and the like. However, the main form of the conventional photocatalytic technology is to disperse the nano-particles into a reaction system, and to sufficiently utilize the huge specific surface area of the nano-particles to catalyze and decompose pollutants in the sewage so as to achieve the purpose of purifying the sewage.

Therefore, researchers began to embed nano-photocatalytic material supports inside the substrate, such as TiO₂The catalyst is mixed into a fixed carrier, such as glass, stainless steel, fiber, carbon nano tube, polymer and the like, so that the catalyst is directly contacted with flowing liquid, the washing probability of the catalyst is effectively reduced, a base material with high adsorbability is adopted, the efficiency of removing organic pollutants from wastewater is improved, and the post-treatment process of separating the catalyst is avoided.

The photocatalytic film technology is a new reinforced technology for compounding a film and a photocatalyst, has the advantages of cyclic utilization, easy recovery, energy conservation, environmental protection, high efficiency and the like, is widely applied to the fields of biology, environmental protection, chemical industry, metallurgy, energy, petroleum, water treatment and the like, and in recent years, titanium dioxide films are mostly adopted for photocatalysis, but the problems of small contact area, low catalytic effect, short service life and the like exist.

CN107876106A discloses a preparation method of oxidized cellulose loaded titanium dioxide, the oxidized fiber material prepared by the method has higher aldehyde group content, better flatness and higher yield, the agglomeration phenomenon of the sensitized titanium dioxide is less, and the oxidized fiber material is uniformly distributed. However, the cellulose material prepared by the method has poor light transmittance and low specific surface area, cannot fully utilize light energy and can effectively contact target pollutants.

CN106807412A discloses a composite photocatalytic material and a preparation method thereof, the photocatalytic activity of the composite photocatalyst prepared by a deposition reduction method is obviously improved, but the composite photocatalyst is not easy to separate from a water body or an environmental medium, and Ag/AgCl is loaded with Bi₆NbWO₁₄The Cl nano-particles are used as a catalyst for environmental pollution treatment to cause secondary pollution.

Disclosure of Invention

The invention aims to solve the problems of insufficient environmental protection and low catalytic activity of the photocatalytic material in the prior art.

In order to achieve the above object, a first aspect of the present invention provides a method for preparing a visible-light-responsive organic-inorganic hybrid film, comprising the steps of:

(1) contacting and mixing a silver nitrate solution with polyurethane to obtain a mixed solution I, wherein the concentration of the silver nitrate solution is 0.05-0.20 mol/L;

(2) contacting the mixed solution I with sepiolite and cerium oxide to obtain a coating solution, wherein the sepiolite is sepiolite powder with the average particle size of 1-3 mu m, and the cerium oxide is cerium oxide powder with the average particle size of 2-5 mu m;

(3) coating the film coating liquid on a substrate to obtain the substrate coated with the film coating liquid, and after 0-3 minutes, carrying out contact reaction I on the substrate coated with the film coating liquid and a YX solution to obtain a hybrid film deposited with in-situ generated AgX nano particles, wherein X is selected from at least one of Cl, Br and I, and Y is selected from at least one of Na, K and Ga;

(4) and (3) carrying out illumination treatment on the hybrid membrane under an ultraviolet lamp to obtain the organic-inorganic hybrid membrane responding to visible light.

A second aspect of the present invention provides a visible-light-responsive organic-inorganic hybrid film.

In a third aspect of the invention, there is provided a use of a visible light responsive organic-inorganic hybrid film for degrading contaminants.

Compared with the prior art, the preparation method and the obtained product have the following advantages:

(1) the visible light responding organic-inorganic hybrid membrane adopts polyurethane, cerium oxide, sepiolite and the like, silver halide nano particles such as AgX (X is Cl, Br or I) and the like are generated in situ in the wet phase conversion process, the generated silver halide nano particles are firmly supported and uniform in particle size, the spectral response range of the composite membrane is greatly expanded, and the photocatalytic activity for pollutant degradation is improved.

(2) The organic-inorganic hybrid membrane responsive to visible light can be reused in practical application, has good stability, does not need filtration and centrifugation in the recovery process, greatly avoids the problem of secondary pollution of nano particles in water, and can be used as a high-efficiency antibacterial membrane, thereby realizing the multifunctional application of the composite membrane.

(3) The invention indirectly regulates the particle size, distribution and particle layer thickness of silver halide nanoparticles generated on the organic-inorganic hybrid membrane with visible light response by regulating the concentration of silver nitrate, thereby regulating the performance of the hybrid membrane.

Through the technical scheme, the organic-inorganic hybrid membrane prepared by the invention has excellent visible light response photocatalysis performance, can be used as an efficient antibacterial material, has better antibacterial capability, is simple in preparation method, and has stable structure, easy recovery and good market application prospect.

Drawings

FIG. 1 is a surface electron microscope image of a visible-light-responsive organic-inorganic hybrid film prepared in example 2;

FIG. 2 is a cross-sectional electron microscope image of the visible light-responsive organic-inorganic hybrid film prepared in example 2.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

As described above, the first aspect of the present invention provides a method for preparing a visible-light-responsive organic-inorganic hybrid film, comprising the steps of:

(3) coating the film coating liquid on a substrate to obtain the substrate coated with the film coating liquid, and after 0-3 minutes, carrying out contact reaction on the substrate coated with the film coating liquid and a YX solution to obtain a hybrid film deposited with in-situ generated AgX nano particles, wherein X is selected from at least one of Cl, Br and I, and Y is selected from at least one of Na, K and Ga;

Preferably, in the step (1), the silver nitrate solution is obtained by mixing silver nitrate with at least one organic solvent selected from the group consisting of N, N-dimethylformamide and N, N-dimethylacetamide.

Preferably, the concentration of the silver nitrate solution is 0.08-0.15mol/L, under the preferable condition, the method can enable the nano silver particles to be effectively immobilized in the surface and internal pore structures of the hybrid membrane and to be uniformly dispersed, so that a compact and continuous silver particle layer is formed, a better spectral response range is obtained, and the utilization rate of the hybrid membrane on visible light is remarkably enhanced.

Preferably, in the step (1), the polyurethane is polyester type thermoplastic polyurethane particles with the average particle diameter of 2.0-5.0 mm, and the Shore hardness of the polyurethane is 55A-65A.

Preferably, in the step (1), the mass ratio of the silver nitrate solution to the polyurethane in terms of pure substances is 1: 5-20.

Preferably, in step (1), the contact mixing I is carried out in the presence of stirring at a speed of 350-500rpm for 5-40 h.

Preferably, in step (1), the temperature of the contact mixing I is 15-45 ℃.

According to a particularly preferred embodiment, in step (1), the contact mixing is carried out under exclusion of light.

Preferably, in the step (2), the amount mass ratio of the mixed solution I, the sepiolite and the cerium oxide is 1: 0.05-0.2: 0.05-0.2.

Preferably, in the step (2), the step of contacting the mixed solution I with sepiolite and cerium oxide comprises: firstly, the mixed solution I is contacted with sepiolite, the first stirring is carried out for 5-20min, then the mixed solution I is contacted with cerium oxide, the second stirring is carried out for 5-30min, and then the obtained mixed solution II is kept stand for 2-5 h.

Preferably, in the step (2), the speed of the first stirring and the speed of the second stirring are respectively and independently 350-500 rpm.

Preferably, in the step (3), the concentration of the YX solution is 0.005-0.025 mol/L.

Particularly preferably, the YX solution is selected from at least one of potassium chloride, potassium bromide, and potassium iodide solutions.

More preferably, the concentration of the YX solution is 0.01 to 0.02 mol/L. The inventors found that in this preferred case, the hybrid membrane prepared has better visible light catalytic activity.

According to a particularly preferred embodiment, the YX solution is an aqueous solution of YX.

Preferably, in the step (3), the contact reaction I is carried out for 3-10h at the temperature of 15-45 ℃;

preferably, in step (3), the substrate is a glass substrate.

Preferably, in the step (3), the coating solution is used in an amount such that the thickness of the film on the substrate coated with the coating solution is 50 to 90 μm.

Preferably, the step (3) further comprises sequentially performing cleaning I and freeze drying I on the hybrid film deposited with the in-situ generated AgX nanoparticles.

Preferably, the solvent of the washing I is water, the temperature of the freeze drying I is 55 ℃ below zero to 35 ℃ below zero, and the time of the freeze drying I is 1-8 h.

According to a particularly preferred embodiment, the cleaning I is carried out by washing and then soaking, the washing times are 2-5 times, the soaking temperature is 15-35 ℃, and the soaking time is 0.5-3 h.

Preferably, in step (4), the condition of the light treatment at least satisfies: the power is 20-40W, the wavelength is 350-380nm, and the illumination time is 20-80 min.

It should be noted that the present invention has no particular limitation on the manner of the light treatment, and a specific operation method is exemplarily provided in the following examples of the present invention, and those skilled in the art should not be construed as limiting the present invention.

As described above, the second aspect of the present invention provides a visible-light-responsive organic-inorganic hybrid film obtained by the aforementioned method for producing a visible-light-responsive organic-inorganic hybrid film.

As previously mentioned, the third aspect of the present invention provides the use of the aforementioned visible light-responsive organic-inorganic hybrid film for degrading contaminants.

In particular, in step (3), the interval time is a timing starting point when the coating solution is completely applied and a timing ending point when the substrate coated with the coating solution is placed in the YX solution.

The present invention will be described in detail below by way of examples. In the following examples, unless otherwise specified, all the raw materials used were analytical commercially available products, and all the equipment used were general industrial production equipment.

In the present invention, the room temperature or room temperature referred to in the following examples is 25. + -. 3 ℃ unless otherwise specified.

Silver nitrate: analytically pure, purchased from Tianjin Kemiou Chemicals, Inc.

Polyurethane I: shore hardness was 55A, purchased from Dongguan Xingwang Plastic materials Co.

And (2) polyurethane II: shore hardness is 60A, and is purchased from Dongguan Xingwang plastic materials Co.

Polyurethane III: shore hardness is 65A, purchased from Dongguan Xingwang Plastic materials Co.

N, N-dimethylformamide: purchased from Guangdong Guanghua technologies, Inc.

Sepiolite powder I: the average particle size was 1 μm and was purchased from Shijia Tianyuan mining Co., Ltd.

Sepiolite powder II: the average particle size was 2 μm and was purchased from Shijia Tianyuan mining Co., Ltd.

Sepiolite powder III: the average particle size was 3 μm and was purchased from Shijia Tianyuan mining Co., Ltd.

Cerium oxide powder I: the average particle size was 2 μm and was purchased from Aladdin Biotechnology Ltd.

Cerium oxide powder II: the average particle size was 3 μm and was purchased from Aladdin Biotechnology Ltd.

Cerium oxide powder III: the average particle size was 4 μm and was purchased from Aladdin Biotechnology Ltd.

Cerium oxide powder IV: the average particle size was 5 μm and was purchased from Aladdin Biotechnology Ltd.

Potassium chloride: analytically pure, purchased from chemical reagents of national drug group, ltd.

Potassium bromide: analytically pure, purchased from chemical reagents of national drug group, ltd.

Potassium iodide: analytically pure, purchased from chemical reagents of national drug group, ltd.

A freeze dryer: model LC-10N-50D, available from Shanghaineqi Instrument science and technology, Inc.

Ultraviolet lamp: model number Philips-36W, light intensity 36W, wavelength 365nm were purchased from the Homephitis Lighting Inc.

Xenon lamp: PLS-SXE300, available from Beijing Pofely technologies, Inc.

A biochemical incubator: LRH-250-A, purchased from medical instruments, Guangdong province.

Staphylococcus aureus: purchased from Ningbo Ming boat Biotechnology, Inc. under the designation B66106.

Coli: purchased from Ningbo Ming boat Biotechnology, Inc. under the designation B81158.

Beef extract, 01-009-1, was purchased from Macbog biotech, Inc., Beijing.

Peptone, 01-001, available from MacoBoxing Biotechnology, Inc., Beijing.

Agar powder, 01-023, was purchased from Aobo Star Biotech, Inc., Beijing.

Sodium chloride, GR (Shanghai test), was not less than 99.8 wt%, and was purchased from national pharmaceutical group chemical reagents, Inc.

Preparing a silver nitrate solution: at normal temperature, a certain amount of silver nitrate is weighed and mixed with the N, N-dimethylformamide solvent, and the mixture is stirred until the silver nitrate is completely dissolved to obtain a silver nitrate solution.

Preparation of potassium halide solution: at normal temperature, weighing a certain amount of potassium halide, mixing the potassium halide with water, and stirring until the potassium halide is completely dissolved to obtain a silver nitrate solution to obtain a potassium halide solution, wherein the potassium halide is respectively potassium chloride, potassium bromide and potassium iodide.

Example 1

The preparation method of the visible light response organic-inorganic hybrid membrane comprises the following steps:

(1) 65ml of silver nitrate solution with the concentration of 0.08mol/L is contacted with 7g of polyurethane I, and the mixture is magnetically stirred (350rpm) for 24 hours under the conditions of normal temperature and light shielding, so that the polyurethane I is completely dissolved to obtain a mixed solution I.

(2) And (3) firstly contacting the mixed solution I with 2g of sepiolite powder I, carrying out first stirring (350rpm) for 10min, then adding 10g of cerium oxide powder I, then continuing to carry out second stirring (350rpm) for 15min, and standing for defoaming for 3h to obtain the coating solution.

(3) And coating the film coating liquid on a glass plate (the thickness of the film coating liquid is 80 mu m), and soaking the glass plate coated with the film coating liquid into 520mL of potassium chloride solution with the concentration of 0.01mol/L within 0 minute for contact reaction for 8 hours to obtain the hybrid film deposited with the in-situ generated AgCl nano particles.

(4) And taking the hybrid membrane out of the potassium chloride solution, washing with deionized water for three times, soaking in the deionized water for 2 hours to remove impurities on the hybrid membrane, and drying in a freeze dryer at the temperature of-55 ℃ for 3 hours to obtain the hybrid membrane deposited by AgCl nano particles.

(5) And (3) respectively illuminating the front side and the back side of the dried hybrid membrane for 30 minutes under an ultraviolet lamp to reduce the AgCl nano particles into Ag simple substance, thus obtaining the visible-light-responsive organic-inorganic hybrid membrane, and naming the organic-inorganic hybrid membrane as S1.

The remaining examples were carried out using the same procedure as in example 1, except that no particular indication was made, and the parameters were as shown in Table 1.

Comparative example 1

Unless otherwise specified, comparative examples were carried out using the same procedure as in example 2, with the different parameters listed in table 2.

The remaining comparative examples were carried out using the same procedure as in comparative example 1, except that no particular indication was made, and the parameters were as shown in Table 2.

TABLE 1

TABLE 2

Test example 1

Surface morphology and cross-sectional morphology characterization: the surface morphology and the cross-sectional morphology of the visible-light-responsive organic-inorganic hybrid film prepared in example 2 were characterized by using a field emission scanning electron microscope (FESEM, mitcan corporation, czech republic of TESCAN 3), and the specific electron micrographs are shown in fig. 1 and fig. 2.

As shown in figure 1, Ag/AgX nano particles are successfully generated in situ on the surface of an organic-inorganic hybrid membrane responding to visible light, the solid support is firm, no obvious agglomeration phenomenon exists, and the average grain diameter of crystals is 100-500 nm;

as shown in fig. 2, it can be seen that the organic-inorganic hybrid membrane with visible light response has an obvious asymmetric porous structure, which provides a large space for the adsorption of organic pollutants, and is beneficial to accelerating the degradation of pollutants on the hybrid membrane.

Test example 2

The degradation rate of the organic-inorganic hybrid film with visible light response prepared in the examples and the comparative examples is detected by taking methyl orange as an organic pollutant:

cutting the prepared visible light response organic-inorganic hybrid membrane into 4cm multiplied by 4cm by taking a 300W xenon lamp with a 420nm ultraviolet cut-off filter as a visible light source, respectively soaking the membrane into methyl orange solution (50ml, 10mg/L), and performing dark treatment for 30 minutes before turning on the visible light lamp; the distance between a xenon lamp light source and the organic-inorganic hybrid film responding to the visible light is 15cm, the degradation rate of the organic-inorganic hybrid film responding to the visible light to the methyl orange within 100min is tested, and the calculation formula of the degradation rate is as follows: [ (initial concentration-concentration after degradation)/initial concentration ] × 100%, wherein the units of the initial concentration and the concentration after degradation are both mg/L, the specific test results are shown in Table 3.

Test example 3

The test example uses staphylococcus aureus (gram positive bacteria) and escherichia coli (gram negative bacteria) as typical representatives, and evaluates the antibacterial activity of the visible light response organic-inorganic hybrid membrane prepared by the invention by a disc diffusion method.

All glassware and medium solutions were sterilized in a vertical automated electric pressure steam autoclave at 120 ℃ for 21 minutes prior to testing. The entire test procedure was performed under sterile conditions.

A beef extract peptone medium (formulation: 3g beef extract, 10g peptone, 5g sodium chloride, 15g agar powder and 1000ml deionized water) was prepared in advance.

The specific method comprises the following steps:

(1) pouring 30ml of beef extract peptone culture medium into a culture dish, and standing to solidify;

(2) respectively and uniformly inoculating 1mL of staphylococcus aureus culture solution and 1mL of escherichia coli culture solution on two different culture media through an inoculating loop;

(3) respectively cutting the organic-inorganic composite photocatalytic film subjected to sterile treatment into round sheets with the diameter of 10mm, and lightly pressing the round sheets by using sterile forceps to enable the round sheets to be adhered to a culture medium;

(4) the culture dish is placed in a biochemical incubator and cultured for 24 hours at 37 ℃, the antibacterial performance of the organic-inorganic hybrid membrane responding to visible light is evaluated according to the diameter of the inhibition ring, 5 groups of parallel experiments are carried out in total, and the specific result is shown in table 4.

Table 3: degradation Properties

	S1	S2	S3	S4	S5	S6	D1	D2
									Degradation time/min	100	100	100	100	100	100	100	100
Percent of degradation/%)	91.19	98.21	93.0	95.16	75.16	79.33	51.08	21.14

Table 4: antibacterial activity

As can be seen from the results of table 3, the visible light-responsive organic-inorganic hybrid film of the present invention has good degradation properties.

The results in table 4 show that the visible light-responsive organic-inorganic hybrid membrane prepared by the invention has an obvious inhibition zone around the membrane, which indicates that the visible light-responsive organic-inorganic hybrid membrane prepared by the invention has good antibacterial activity on staphylococcus aureus (gram-positive bacteria) and escherichia coli (gram-negative bacteria).

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A preparation method of a visible light response organic-inorganic hybrid membrane is characterized by comprising the following steps:

2. The method for preparing a visible-light-responsive organic-inorganic hybrid film according to claim 1, wherein, in the step (1), the silver nitrate solution is obtained by mixing silver nitrate with at least one organic solvent selected from the group consisting of N, N-dimethylformamide and N, N-dimethylacetamide;

preferably, the concentration of the silver nitrate solution is 0.08-0.15 mol/L.

3. The method for preparing a visible-light-responsive organic-inorganic hybrid film according to claim 1 or 2, wherein, in the step (1), the polyurethane is polyester type thermoplastic polyurethane particles having an average particle diameter of 2.0 to 5.0 mm, and the shore hardness of the polyurethane is 55A to 65A;

preferably, in the step (1), the mass ratio of the silver nitrate solution to the polyurethane in terms of pure substances is 1: 5-20 parts of;

preferably, in step (1), the contact mixing I is carried out in the presence of stirring at a speed of 350-500rpm for a period of 5-40 h.

4. The method for producing a visible-light-responsive organic-inorganic hybrid film according to any one of claims 1 to 3, wherein in the step (2), the mixed solution I, the sepiolite and the cerium oxide are used in a mass ratio of 1: 0.05-0.2: 0.05-0.2.

5. The method of preparing a visible-light-responsive organic-inorganic hybrid film according to any one of claims 1 to 4, wherein the step of contacting the mixed solution I with sepiolite and cerium oxide in the step (2) comprises: firstly, the mixed solution I is contacted with sepiolite, the first stirring is carried out for 5-20min, then the mixed solution I is contacted with cerium oxide, the second stirring is carried out for 5-30min, and then the obtained mixed solution II is kept stand for 2-5 h.

6. The method of preparing a visible-light-responsive organic-inorganic hybrid film according to any one of claims 1 to 5, wherein, in the step (3), the concentration of the YX solution is 0.005 to 0.025 mol/L.

7. The method for preparing a visible-light-responsive organic-inorganic hybrid film according to any one of claims 1 to 6, wherein, in the step (3), the contact reaction I is carried out for 3 to 10 hours;

8. The method for preparing a visible-light-responsive organic-inorganic hybrid film according to any one of claims 1 to 7, wherein, in step (3), the hybrid film deposited with in-situ generated AgX nanoparticles is subjected to washing I and freeze-drying I in sequence;

preferably, the solvent of the washing I is water, the temperature of the freeze drying I is 55 ℃ below zero to 35 ℃ below zero, and the time of the freeze drying I is 1-8 h;

9. The visible-light-responsive organic-inorganic hybrid film obtained by the method for producing a visible-light-responsive organic-inorganic hybrid film according to any one of claims 1 to 8.

10. Use of the visible light-responsive hybrid organic-inorganic membrane of claim 9 for degrading contaminants.